PROJECT SUMMARY The childbearing years are a particularly vulnerable time period for women during which they tend to gain disproportionately large amounts of weight when compared to men or other life periods. Weight gained during pregnancy and retained after the postpartum period contributes to obesity development and progression. Our team developed a lifestyle modification intervention in partnership with Parents as Teachers (PAT), a national home visiting, community based organization with significant reach in this population. PAT provides parent-child education and services free-of-charge to families through frequent home visits every year from the prenatal period until the child enters kindergarten. The intervention (EMPOWER) prevented excessive gestational weight gain and postpartum weight retention by embedding content within the existing PAT visit structure. This study will extend these findings with a pragmatic cluster randomized controlled trial to evaluate dissemination and implementation of EMPOWER across multiple levels (mother, parent educator, PAT site) to achieve widespread impact. We will evaluate the impact of EMPOWER on gestational weight gain and postpartum weight retention among mothers with overweight and obesity across the US (N= 266 EMPOWER; N= 266 usual care). Parent educators from 28 existing PAT sites (14 EMPOWER, 14 usual care) will receive the EMPOWER training curriculum through the PAT National Center using the existing training infrastructure. An extensive evaluation guided by RE-AIM, will determine implementation outcomes (acceptability, adoption, appropriateness, feasibility, fidelity, and adaptation). The Conceptual Framework for Implementation Research will characterize determinants that influence EMPOWER dissemination and implementation at multiple levels (mother, parent educator, PAT site) to enhance external validity (reach and maintenance) and population level impact. The findings from this innovative study will reach young women who have experienced the greatest increase in obesity prevalence in the past 45 years compared to other groups, due in part to weight gain associated with child bearing.